Telephone-exchange system



Jane 29,

F. N. REEVES TELEPHONE EXCHANGE SYSTEM QFiled Dec. 4, 1919 7 4 Sheets-Sheet 1 ti Eb ode Mike/#01.- Fran/r /l Ree V66 F. N. REEVES TELEPHONE EXCHANGE SYSTEM Filed Dec. 4, 1919 4 Sheets-Sheet 2 /n ver: 70/ Fran/r N Reeves.

Jan, 29, 1924. 1,481,969

F. N. REEVES TELEPHONE EXCHANGE SYS TEM Filed Dec. 4, L Sheets-Sheet 5 Wye/7 0/: Fran/r /V. 5'661/65.

Jam, 29 9 1924.

.F. N. REEVES TELEPHONE EXC'HANGE SYSTEM Filed Dec. 4, 1919 4 Sheets-Sheet 4 N2 MAL '//IV/7 for 1,481,969 sTATEs- PATET--0FE1CE.

ream n; EEEvEs, or NE ARK, NEW JERSEY, Assienoa T0 WESIIERN mn'c'rmc COMPANY, INCORPORATED, or NEW roan, n. Y., acoerona'rmn on NEW roan.

TELEPHONE-M CHANGE SYSTEM I.

Application filed December 4, 1919. Serial No: 342,441.

To all whom it may concern:

Be it known that I, FRANK N. REEVES, a citizen of the United States, residin at Newark, in ,the county of Essex and tate of New Jersey, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and particularly to those systems in which machine switching apparatus is used for extending and completin talking connections.

n telephone systems of the character in which register senders are employed for controlling the selective movement of the automatic switches, it is the customary practice to position the registers either by means of a condition set up in response to the operation of the keys on an operators keyboard, or by means of current impulses sent from the transmitter at the calling sub:

station or operators position.

The registers in this manner are caused to take positions representing a desired designation, and thereafter serve to control the selective operation of the switches to establish the desired connection.

It is the object of this invention to provide in systems of the above general character, means comprising a variably operable mechanism, responsive to series of current impulses, for positioning the registers of the sender in accordance with said impulse series to recordfon said registers the reiuireddesignations.

' ccordingly, one feature of the invention has to do with the provision of means comprisin a plurality of electro-mechanisms arrange to be successively operated in' variable numbers in response to series of ourrent impulses for positioning the sender registers.

Another feature relates to the provision of a series of relays, successively responsive in variable numbers to series of current impulses and arranged to be successively as sociated with the sender registers for positioning these registers in accordance with the digits of wanted numbers.

A still further feature of the invention resides in the provision of a plurality of se ries of relays, each series successively operable in response to current impulses, and arranged to be as'sociatedfin alternate suc- L cession with the several registers of the sender for the purpose of positioning these registers in correspondence with the digits represented by said impulses.

Other and further advantages derived from the present invention will sufficiently appearfrom a consideration of the followmg description and appended claims.

. n the drawings which form a part of this application, Figs. 1, 2, 3 and 4-, when taken with Fig. 2 tothe right of Fig. 1, Fig. 3 below Fig. 1, and Fig. 4 to the right of Fig. 3, illustrate so much of a telephone system as is necessary to an understanding of the invention. Fig. 1 shows a subscribers line, a group selector switch, a line switch for extending the subscribers line to idle group selectors and a sender selector. Fig. 2 shows the circuits of a final selector switch. Fig; 3 illustrates a plurality of electromechanisms for variably positioning the switch controlling registers of the sender. lhis figure also shows the usual counting relay set for controlling the movement of the selective switches in accordance with the setting of the sender registers. Fig. 4 shows the switch controlling registers.

The selective switches, shown in Fi s. 1 and 2, may be of the type describe in Patent No. 1, 123,696, issued to Craft and Reynolds January 5, 1915. For simplicity in the description of the present invention, the group selector switchis assumed to be provided with ten sets of brushes, each having access to a group of trunks leading to final selectors. Likewise, the final selector switches are provided with ten sets of brushes, each set serving ten groups of subscribers lines each .group comprising ten lines. By thus arranging the grouping of trunks and lines on a decimal basis, the necessity of translation is obviated. lit is to be understood, however, that the invention is equally well adapted to systems in which translation is involved, the omission of this feature being merely to simplify the description of the operation.

The sequence switches, which are used for making the necessary circuit changes in this disclosure, may be of the construction shown in the patent to Reynolds and Baldwin, No. 1,127,808, issued February 9, 1915. Where but one of these sequence switches occurs on a sheet of drawings, it is obvious that all contacts appearing on the same gized in variable numbers in response to series of impulses transmittedfrom a calling subscriber s substation or from an operators position. After the counting relays of the set have been operated in accordance with the number of impulses transmitted, they then become efi'ective to determine the positioning of the sender registers. Inasmuch as the invention is particularly applicable to full automatic systems, it is shown in the present disclosure as embodied in a system 1 of that character. It will be obvious, however, from a consideration of the following description, that in systems where operators take part in the establishment of connections, impulse transmitters may be provided at the operators positions for controlling the setting of the sender registers.

In the detailed description of the operation of the system, which will now be given, it is assumed that the subscriber-at the substation 100 desires to obtain a telephone connection with the substation 200, the'number of which line is 1012. Upon removing his receiver from the switchhook, the calling subscriber at substation 100 closes the line circuit to cause the energization of the line relay 102. Relay 102, attracting its armature, closes a circuit as follows for the stepping magnet 104 of the line switch: Battery, through the armature and contact and winding ofstepping magnet 104 to ground at the front contact and armature of relay 102. Steppingmagnet 104' interrupts its own circuit and advances the brushes 105, 106 and 107 over the terminals of trunks leading to group selecton switches.

As soon as the test brush 107 engages-the the line switch to come to rest on the terminals of the idle trunk, Relay 111 becomes energized at the same time and completes a circuit from ground through its armature and contact, winding of sequence switch 120 to battery and ground. Sequence switch 120 moves out of position 1. On

leaving position 1 sequence switch 120 opens the circuit of relay 111 so that said sequence switch stops in position 2. The cutoff relay 103 is maintained energized by means of a substitute circuit including sequence switch contact 112 and resistance 152.

In positio'n 2 of sequence switch .120 the sender selector, whose brushes are shown at 119, 121, '122, 123, 124 and 125, is set in operation to find an idle register sender and associate the same with the circuits of the group selector switch. The circuit for the stepping magnet 117, which operates the brushes of the sender selector, may be traced from battery through the winding of said magnet, armature and contact thereof, contact 118 (2) to ground at the contact and left-hand armature of relay 116. The brushes of the sender selector advancestepby-step until an idle sender is reached, at which time a circuit is closed from battery through the winding of relay 1'16, brush 119, conductor 153, contact 302(1) of sequence switch 300, winding of relay 319 to ground. Relay 116 energizes and opens at its lefthand armature the circuit for stepping magnet 117. The brushes 119, 121, 122, 123, 124 and 125, therefore, stop on the terminals corresponding 'to an idle register sender. Relay 116 at its right-hand armature completes a circuit including contact 115 (2) for driving sequence switch 120 out of position 2 and into position 3. The relay 319, which energizes in series with relay 116, closes a circuit from ground through its armature and contact, contact 301 (1), winding of sequence switch 300 to battery and ground. The closure of this circuit causes the sequence switch 300 to advance from position 1 into position 2.

As soon as the sender selector has found an idle sender, a circuit is established from battery through the left-hand winding of stepping relay 303, conductor 154, brush 122, contact 126 (3), terminal 108, brush 105 over the loop of the'calling line, brush 106, terminal 109, contact 127 (3), brush 121, conductor 155, right-hand winding of relay 303 to ground. This circuit, which includesthe calling subscribers substation in series therewith, comprises the impulse'circuit over which series of impulses are sent by the calling subscribers transmitter 101 to causethe positioning of the sequence switch registers. For the first series of impulses which represents the first digit of the called number, the first set of counting relays, shown at the top of Fig. 3, is associated with the stepping relay 303. Relay 303 by attracting its right-hand armature closes an energizing circuit for the slow-to-releas relay 304. Relay 304 completes a circuit from ground through its right-hand armature and contact, switch arm-310, conductor 331, contact and right incisor hand armature of relay 401, winding of thousands register 400 to battery and ground. The register 400, energizing in. this circuit, leaves the position in which it happens to be resting and commences to rotate. I

The switch arm 310, over which the above traced circuit is established, is one of a lurality of switch arms comprising a steermg switch, whose function it is to alternately associate the stepping relay 303 first with one and then with the other of the sets of counting relays. The steering switch arms 307, 308, 309, 310, 311' and 312 are controlled by means of the stepping magnet 313, which is arranged to advance said arms on its deenergization.

The calling subscriber now manipulates his transmitter 101 to send, one impulse corresponding to the first digit of the desired number. The interruption of the impulse circuit causes the release of the stepping relay 303. Relay 303 closes a circuit from ground over its left-hand armature and contact, contact and left-hand armature of relay 304, winding of slow-to-release relay 305, steering switch arm 307 (first position), conductor 332, left-hand armature and back contact of the No. 1' relay 334 of the first counting relay set, winding of the Np. 1 relay 335, contact and left-hand armature of relay 320 to battery and ground. The No.1 counting relay 335 energizes in this circuit and prepares a circuit for the No. 1 counting relay 334 in series therewith by the closure of its left-hand armature and contact. The No. 1' relay 334, however, does not energize at this time since it is shunted by the direct path to ground atthe left-hand armature and back contact of the stepping relay 303. The slow-to-release relay 305 energizes and closes a circuit from ground through its armature and contact, winding of the stepping magnet 313 to battery and ground. The stepping magnet 313 energizes 'preparatory to advancing the switch arms into the second position. Upon the closure ofthe impulse-circuit at the termination of the first impulse, the stepping relay 303 be: comes energized and opens the above traced circuit for the No. 1 counting relay 335. Thisremoves the shunt from around the No.. 1 counting relay 334 and these relays enerize and lock up in the following circuit:

attery, left-hand armature and contact of relay 320 throu h the windings of the No. 1 and No. 1' re ays 335 and 334 in series, left-hand armature and contact of relay 335 to ground. The slow-to-release relays 304 and 305 do not retract their armatures due to the brief energization and deenergization of the stepping relay 303 that take place during the transmission of a series of impulses from the subscribers transmitter. While, however, the calling subscriber is resetting the transmitter 101 after having sent the first digit, the stepping relay 303 maintains its armatures attracted for a period of impulses sent by the calling subscriber in accordance with the first digit. In position 1 of the register 400 a circuit.is established from battery through the winding of relay 401, contact 403 (1), conductor 333,

contact and right-hand armature of the No.

1 counting relay 334, back contacts and right-hand armatures of the No. 2, No. 3,

No. 4' relays and so forth to ground at the back contact and right-hand armature of the No. 0 relay "376. Relay 401 energizes and opens the circuit of the register 400 permitting said register to stop in position 1. Relay 401 closes a circuit from battery through its winding and contact and lefthand armature, winding of relay 402, conductor 336, switch arm 309 (position 2) to ground. With the register 400 in position 1 and with relay 402 energized in series with relay 401, a circuit is completed from battery through the winding of relay 320, conductor 337, left-hand armature and contact of relay 402, contact 404 (1), conductor 338, contact and right-hand armature of relay 335, back contacts and right-hand up in a circuit from battery through its windings and contact andright-hand armature to gro nd at switch arm 308, The attraction of he left-hand armature of relay for the counting relays whereupon relays 335 and 334 are released. It will beobserved from the above description that the register 400 stops in a position correspond.-

ing to the-digit sent by the calling subscriber and cannot stop inany other position since the circuit is not completed for the stop re-. lay 401 until said register has reached a position corresponding to the number of pairs of counting relays that are energized and locked up.

As above noted, the steering switch advanced from position 1 into position 2 at the termination of the first series of impulses. This olperation of the steering switch disassociates t e stepping relay 303 from.

320' opens the above traced locking circuit gins to rotate.

the first set of counting relays and associates such relay with the second set of countin relays preparator to setting the hundre s register 410. s the steering switch reached position 2 a circuit was completed from ground through the contact and right-hand armature of relay 304, swltch arm 310 (position 2), conductor 340, con tact and right-hand armature of relay 411, winding of the hundreds register 410 to battery and ground. The register 410 leaves the position in which it is standing and be- The calling subscriber now operates his dial 101 to send ten impulses representing the second digit of the wanted number. gizes at the first interruption of the impulse circuit and completes a circuit from ground through its left-hand armature and contact, contact and left-hand armatures of relay 304, winding of relay 305, switch arm 307 (position 2), conductor 341, left-hand armature and back contact of the No. 1' counting relay 342, winding of the No. 1 counting relay 343, contact and left-hand armature of relay 330 to battery and ground. Relay 343 becomes energized and prepares a circuit at its left-hand armature and contact for the energization of relay 342. Relay 342, however, 1s shunted out by the direct path to ground at the back contact and left-hand armature of relay 303. Relay 305 energizes in series with relay 343 and closes a circuit for the energization of the stepping magnet 313. As soon as the impulse circuit is closed at the termination of the first impulse, relay 303 attracts its armatures and removes the shunt from around the No. 1 counting relay 342. Relays 343 and 342 are now energized and locked u in a circuit from battery through the leftand armature of relay 330, windings of relay 343 and342 in series, left-hand armature .and contact of relay 343 to ground. At the second interruption of the impulse circuit, relay 303 releases its armatures and closes a circuit from ground over its left-hand armatureand contact, contact and left-hand armature of relay 304, winding of relay 305, switch arm 307 (position 2), conductor 341, left-hand armature and front contactof relay 342, left-hand armature-and back contact of the No. 2' relay 344, Winding of the No. 2 counting relay 345, contact and left-hand armature of relay 330-to battery and ground. Relay 345 attracts its armatures and upon the next closure of the impulse circuit the shunt is removed from.-around relay 344, permitting relays 345 and 344 to energize and lock up in the manner already described. This procedure continues, a pair of counting relays being ener ized and locked up for each impulse, until the last impulse of the series is sent, at which time the'O and 0 relays 346 The stepping relay 303 deener-- and 347 are energized. At the termination of the second series of impulses theslow to lays 401 and 402. In position 3," switch arm 311 closes a substitute circuit to maintain the energization of the hundreds register 410, the original energizing circuit of which has been opened as switch arm 310 leaves position 2. The hundreds register 410 rotates until it reaches position 0 which corresponds to the second digit of the called number. In this position a circuit is closed from battery through the winding of relay 411, contact 413 (0), conductor 348, front contact and right-hand armature of the 0 relay 347 to ground. Relay 411 attracts its armatures and opens the operatin circuit of register 410. Register 410, there ore, ceases to rotate. Relay 411 completes a circuit from battery through its winding and contact and left-hand armature, winding of relay 412, conductor 349, switch arm 309 (position 3) to ground. With the register 410 in position 0 and relay 412 energized, a circuit is established from battery through the winding of relay 330, conductor 350, armature and contact of relay 412, contact 414 (0), conductor 351, front contact and righthand armature of relay 346, conductor 352, switch arm 308 (position 3) to ground. Relay 330 becomes energized in this circuit and opens the locking circuit of the counting relays, whereby these relays are restored to their normal positions. Relay 330 at its right-hand armature closes a locking circuit for itself including switch arm 308 in position 3.

The steering switch having been advanced into its third position following the transmission of the second series of impulses, stepping relay 303 is now associated with the first set of counting relays ready to control the positioning of the tens re ister 420. As the steering switch is advanced into position 3 a circuit is established from ground through the contact and right-hand armature of relay 304, switch arm 310 (position 3), conductor 353, contact and right-hand armature of relay 421, winding of register 420 to battery and ground. Register 420 energizes in this circuit and commences to rotate. The calling subscriber manipulates his dial 101 in accordance with the third digit 1 to send a single impulse. Relay 303 deener izes in response to the interruption of the ine circuit and closes a circuit from ground menace through its left-hand armature and contact, contact and left-hand armature of relay 304, winding of relay 305, switch arm 307 (position 3), conductor 332, left-hand armature and back contact of the No. 1' relay 334, winding of the No. 1 rela 335, contact and left-hand armature of re ay 320 to .battery and ground. Upon the closure of the impulse circuit the No. 1' relay 334 energizes and locks up in series with the No. 1 relay. In the manner above described, the tens register 420 is caused to vstop in position 1 and relay 421 is energized. At the termination of the third series of impulses relay 305 releases its armature and opens the energizing circuit of the stepping magnet 313. Magnet 313 consequently advances the steering switch into position 4. On leaving position 3, the switch-arm 308 opens the circuit of relay 330, and switch arm 309 opens the circuit of relays 411 and 412.

In position 4 of the steering switch relay 320 is locked up in a circuit including switch arm 308, and relays 421 and 422 are locked up in a circuit including switch arm 309. In position 4 of thesteerin switch a circuit is established from groun through the contact and right-hand armature of re lay 304, switch arm 310 (position 4), conductor 355, contact and right-hand armature of relay 431, winding of the units register 430 to battery and ground. The register 430 energizes and commences to rotate.

'Ihe calling subscriber operates the trans mitter 101 to send two impulses in accordance with the final digit of the called number. At the first interruption of the line relay 303 releases its armature and closes a circuit from ground through its left-hand armature and contact, contact and lefthand armature of relay 304, winding of relay 305, switch arm 309 (position 4), left-hand armature and back contact of the No. 1'

counting relay 342, winding of relay 343,.

contact and left-hand armature of relay 330 to battery and ground. Relay 343 ,energizes and prepares a circuit for relay 342. When the impulse circuit is again closed relay 303 energizes and-removes the shunt from around relay 342 so that relays 343 and 342 energize and lock up in series with each other. In response to the next and tinal impulse of the series the second pair of counting relays are energized. After the lapse of the required interval following the transmission of the final series of impulses the relay 305 releases its armature and opens the energizing circuit oft-he stepping magnet 313. The steering switch is thereupon advanced from position 4 into position 5. On leaving position 4 the circuit of relay 320 is opened at switch arm 308 and the 'circuit of relays 421 and 422 is opened at switch arm 309. As soon as the units register 430 reaches position 2, a circuit is completed from battery through the winding of relay 431, contact 435 (2), conductor 356 front contact and right-hand armature of 309 (position 5) to ground. With the reg-- ister 430 in position 2 and relay 432 energized a circuit is closed from battery through the winding of relay 330, conductor 350, left-hand armature and contact of relay 432, contact 436 (2), conductor 358, front contact and right-hand armature of relay 345, back: contacts and. right-hand armatures of all the lower counting relay's succeeding relay 345, conductor 352, switch arm 308 (position 5) to ground. Relay 432 closes a circuit from ground through its right-hand armature and upper contact, conductor 359, switch arm 312 (position 5), contact and armature and winding of magnet 313 to battery and ground. Magnet 313 energizes and, interrupting its own circuit, causes the advance of the side switch into its normal position. In leaving, position 5 the circuit of relay 330 is opened at switch arm 308 and the circuit of relays 431 and 432 is opened at switch arm 309.

After the units register has been positioned and when relay 432 attracts its armatures a circuit is established from ground through the right-hand armature and lower contact of relay 432, conductor 360, contact 301 (2), winding of sequence switch 300 to battery and ground. Sequence switch 300 thereupon moves out of position 2 and into position 3. The fundamental circuit is now completed for controlling the operation of the group selector, shown in Fig. 1, in its brush selecting movement. This circuit may be traced from battery throu h the winding of,relay 139, contact 134 (3), brush 123, conductor 156, winding of t e stepping relay 318, outer armature and contact of the No. 1 counting relay 361, contact 314. (3), conductor 157, brush 124, contact 132 (3) to ground. Relay 139 energizes and completes a holding circuit for itself over its contact quence switch contact 134. Relay 139 also establishes a circuit from ground through its right-hand armature and front contact, contact 140 (3), winding of sequence switch 120 to battery and ground. Sequence switch 120 moves out of position 3 andjnto position 4. In position 4 of sequence switch 120 the updrive power magnet 142 is energized in a circuit including contact 140 (4) and the l and left-hand armature independent of se- 7 rela 139. The magnet 142 causes the brush sha t 157 to be moved upward by the power drum 158. The stepping relay 318, which also energizes in the fundamental circuit, closes a circuit from ground through its armature and contact, contact 316 (3), conductor 362, contact 405 (1), conductor '363, winding of relay 364 to battery and ground. Relay 364 attracts its armature and prepares a circuit for relay 361 in series therewith. Relay 361, however, doesnot energize since it is short-circuited by the ground at the arma ture and front contact of relay '318.

When the brush shaft 157 of the group selector advances the brush 144 into engagemcnt with the first metallic segment of the commutator 159, the following circuit is closed for relay 139: Battery through the winding and contact and left-hand armature of said relay, contact 133 (4), commutator 159, brush 144 to ground. This direct circuit to ground shunts the stepping relay 318 in the well-known manner. Relay 318 releases its armature and removes the shunt from around the No. 1 counting relay 361.

-Relays 364 and 361 are thereupon energized in a circuit from battery through the windings of said relays, contact and armature of relay 364, contact 317 to ground. Relay 361 at its inner armature closes a circuit including contact 315' (3) for driving sequence switch 300 out of position 3 and into position 5. In passing from position 3 to r position 5 the sequence switch contact 3l'7'is opened to permit the deenergization of the counting relays. The relay 361 upon energizing opens the fundamental circuit at its outer armature. The relay 139, however, remains energized until the brush 124 reaches the next insulating section of the commutator 159. Relay 139 then releases its armatures and a circuit is completed from ground over the right-hand armature and back contact of relay 139, contact 135 (4), winding of sequence switch 120 to battery and ground. Sequence switch 120 energizes and advances into position 5.'

l-Vith sequence switch 120 in position 5 a circuit'is established from battery through the \vinding'of relay 139, contact 134 (5), contact 138 '(5) to ground. Relay 139 ener-' gizes and completes a circuit fromground over its right-hand armature and front contact, contact 140 (5), through the winding of sequence switch 120 to battery an ground. Sequence switch 120 advances into position 6.- 'In this position the updrive magnet 142 is again energized and causes the brush shaft 157 v to advance the selected set of brushes over the terminals of the trunk group to search for a trunk leading to an idle final selector. The selected set of brushes are tripped so as to make engagement with the trunk terminals by means of a trip magnet 141 which is energized in a circuit includin se uenoe switch contact 136 '(5 to 6). I the rst trunk in the group is busy a ground will be present on the test. terminal thereof, and relay 139 is maintained energized in position 6 of sequence switch .120 by means of the following circuit: Battery through the winding or relay 139, contact and left-hand armature ofsaid relay, contact 134 (6), brush 147, test terminal and thence to ground over the test brush and contact -161'at some other 'grou selector. As soon as an idletrunk is reache the relay 139 deenergizes and closes a circuit from ground through its right-hand armature and back contact, contact 135 (6), winding of sequence switch 120 to battery and ground. Sequence switch 120 advances into position 8. A ound is placed upon the test terminal 150 o the selected trunk by the. closure of contact 161 in positions 7 to 18 to prevent the seizure of this trunk by other switches.

The fundamental circuit is now extended through to the final selector switch and mav be traced from battery through the winding of relay 206, contact 207 (1), contact 202 1), terminal 149, brush 146, contact 130 (8), brush. 124, conductor 157, contact 314 (5 contact and outer armature of relay 361, winding of relay 318, conductor 156, brush 123, contact 129 (8), brush 145, terminal 148, contact 201 (1) to ground. Helay 206 becomes energized and completes a circuit from ground through its right-hand armature and front contact, contact 205 (1), winding of relay 203 to battery and ground. Relay 203 is energized and locks up in a circuit from battery through the winding and contact and left-hand armature of said relay, terminal 150, brush 147 toground at sequence switch contact 161. The relay 203 also closes a circuit from ground through its right-hand armature and front contact, contact 204 1), winding of sequence switch 220 to battery and ground. The sequence switch 220 advances from position 1- to position 2. In this position the updrive power magnet 219 of the final selector is energized in a circuit from battery, through the winding of said magnet, contact 214 (2) to ground at the contact and left-hand armature of relay 206. The brush shaft of the finalselector is moved upward in the brush selecting operation. The stepping relay 318 also energizes in the fundamental circuit and closes a circuit from ground through its armature and contact, contact 316 (5), conductor 365, contact 415 (0), conductor 366, armature and back contact of, the No. 0 counting relay 367, winding of the zero counting relay 368 to battery and ground. Relay 368 energizes in this circuit and pre-' pares a circuit for relay 367. In the upward movement of the final selector brush shaft the brush 223 makes engagement with Inn . the first metallic segment of the commutator is energizedand the No. 9 counting relay 369 is energized. In this manner the movement of the final selector continues until it has reached its tenth brush tripping POSI- 'tion, at which time all of the count-mg relays will have been energized. The energization of the No.1 counting relay 361 -ment following theopening of the causes the sequence switch 300 to be ad-. vanced from position 5 to position 7. In moving from position 5 to position 7 contact 317 opens and causes the release of all the energized counting relays. brush 223 reaches the next insulatin seg- Fundamental circuit by relay 361, the rela 206 deenergizes and comp etes .a circuit from ground over its right-hand armature and back contact, contact 209 (2), winding of sequence switch 220. to battery and ground.

Sequence switch 220 advances into position 3. In this position the tri magnet 218 is ener ized in a circuit close at contact 216 so t at on-the next upward movement of the brush. shaft the selected set of brushes are tripped intoengagement with the line terminals.

In position 3 of sequence switch 220 and position 7 of sequence switch 300, thefundamental circuit is again closed to control the group selecting movement of the switch. Relay 206 by energizing closes a circuit from ground through its righthand armature and front contact, contact 209 .(3), winding of se uence switch 220 to battery and ground. his sequence switch moves from position 3 into position 4. In position 4 the updrive power magnet 219 is energized by means of a circuit closed at.

contact 214 and the brush shaft is caused to advance. The stepping relay 318 by energizing closes a circuit from ground over its armature and contact, contact 316 (7 conductor 370, contact 423 (1), conductor 363, winding of relay 364 to battery and ground. On reaching the first metallic segment of the commutator 230, corresponding to .the. first group of ten lines, the brush 223 causes the relay 318 to be short circuited in the manner well understood. On reaching the next insulating portion of the commutator the brush 223 ermits the deenerg'izat-ion of relay 206. Re ay 206 closes a circuit from ground through its right-hand armature When the and back contact, contact 209 (4), windin of 'se uence switch 220 to battery an groun Sequence switch 220 moves out of.

position 4 and into-position 5. Relay 361, which was energized upon thedeenergization of relay 318, closes a circuit including contact 315 (7') for driving sequence switch 300 into position 9.

The fundamental circuit is now closed for the final or units selection and relays 206 and 318 become energized. Relay 206 closes a circuit from ground through its right-' hand armature and front contact, and contact 209 (5) for moving sequence switch 220 into position 6. In this position the updrive magnet 219 is again energized and the selected set of brushes 224, 225 and 226 are advanced over the group of ten terminals containing the .-terminals of the" called line. Relay '318 by energizing closes a circuit from ground throu h its armature and contact, contact 316 9), conductor 372, contact 437 (2), conductor 373, armature and back contart of relay 374 winding of relay .375 to battery and ground. In the manner already. described the proper number of counting relays are energized, after which the fundamental circuit is opened at the sender and sequence switch 300 advances from position 9 into position 1. When the brush 222 reaches the next insulating segment of commutator 231 after the fundamental circuit has been severed at the sender, thelocal circuit for relay 206, which includes contacts 207 and 208, is opened. Relay 206 deenergizes and closes a circuit from ground through its right han'd armature and back contact,-contact 209 (6), winding of sequence switch 220 to battery and ground. Sequence switch 220 advances into position 8.

When the sender sequence switch 300 reaches position 10 after the final or units selection has been completed, a'circuit is established from ground through the contact 306 (10 to 18), conductor 162, brush 125, contact- 137 (8), winding of sequence switch 120 to battery and ground. Sequence switch 120 advances into position 10 where the talking circuit is completed at contacts 129 and 130.

Upon the final selector sequence switch 220 arriving in position 8, a circuit is closed for the application of ringing current tothe called line. This circuit maybe traced from the ringing source 232, relay 233, contact 210 (8), brush 224, terminal 227 over the loop of the called line 200, terminal 228,

brush 225 and contact 211 (s). to ground. The response of the called subscriber causes, in the well-known manner the energization of relay 233. This relay closes a circuit including contact 212 (8) for driving sequence switch 220 into position 10, which is the talking position thereof.

The conversation having been completed the calling subscriber replaces his receiver .on the switchhook, causing the opening of the calling line circuit. This permits the supervisory relay 131 to deenerglze. A oncuit is then closed from ground through the armature and contact of relay 1231, contact 11st, closed from position 4 to position 17, winding of se uence switch 120 to battery and ground. he sequence switch 120 advances from position 10 into position 18. In position 18 of sequence switch 120 the group selector brush shaft is restored to ts normal position by means of the down-drive power manget 143. The circuit for thls magnet is closed at contact 151. On reaching the normal position the brush 144.- engages the contact 163, thus closing a eucuit'including contact 128 (18) for movlng sequence switch 120 into its normal position 1. As soon as test brush 147 leaves terminal 150 the holding circuit of relay 203 is opened. Relay 203 releases its armatures and closes the following circuit: Ground right-hand armature and back contact of relay 203, contact 209 (2 to 17) winding of sequence switch 220 to battery and ground. bequence swltch 220, by means of this circuit, advances into. position 18. In position 18 of sequence switch 220 the final selector brush shaft is returned to its normal position by means of the down-drive power magnet 221. The circuit for the magnet 221 is closed at contact 215 (18). On reaching the normal position a circuit is closed from ground through the brush 222, contact 234, contact 213 (18), winding of sequence switch 220 to battery and ound. Sequence switch 220 thereupon a vances into its normal position 1. The switches and apparatus have thus been completely restored to their normal positions and may be taken for use in establishing subsequent connections.

What is claimed is:

1. The combination in a telephone system of selective switches for extending telephone connections, registers for controlling the selective operation of said switches, a plurality of successively operable electro-mechanisms, means responsive to current impulses for variably operating said electromechanisms, and means dependent on the number of said electro-mechanisms operated for positioning said registers.

2. The combination in a telephone system of selective switches for extending telephone connections, registers for controlling the selective operation of said switches, a series of electro-mechanisms, an impulse circuit, an impulse transmitter for sending impulses over said circuit, means responsive to said impulses for successively operating the elec tro-mechanisms of said series, andmeans dependent on the number of electro-mechanisms operated for determining the positionin of said registers. I

3. I lie combination in a telephone system of subscribers lines, a selective switch for establishing connections between said lines, means for extendin one of said lines to said switch, a plurality of registers for controlling the selective movement of said switch, means for associatin said registers with said line, a series of relays, means for sending impulses over said line, means responsive to such impulses for successively energizing said rela s, and means controlled by said series of re ays for variably setting said registers. Y

4. The combination in a telephone system of subscribers lines, a selective switch for establishing connections between said lines, means for extending one of said lines to said switch, multiposition registers for controlling the selective movement ,of said switch, means for associatin said registers with said line, a roup of re ays, means for sending series 0 impulses over said line corresponding to the digits of called numbers, means responsive to such impulses for successively energizing said relays, and means-dependent upon the number of relays energized in said group for setting said registers.

' 5. The combination in a telephone system of selective switches for extending telephone connections, registers for control ng the selective operation of said switches, a group of electro-mechanisms, means for successively associating said registers with said oup of electro-mechanisms, means responslve to current impulses for variably operating said electro-mechanisms, and means dependent on the number of said electro-mechanisms operated for positioning said registers.

6. The combination in a telephone system of selective switches for extendin telephone connections, registers for controlfing the selective operation of said switches, a series of relays, a circuit controlling switch for successively associating said registers with said series of relays, means for successively energizing the relays of said series, and means controlled by said series of relays for variably positioning said registers.

7. The combination in a telephone system of subscribers lines, a selective switch for establishing connections between said lines, means for extending one of said lines to said switch, registers for controlling the selective operation of said switch, a series of relays, means for successivel associating said register with said series 0 relays, means for sending impulses over said line, means responsive to such impulses for energizing said relays, and means controlled by said series of re lays for variably setting said registers.

8. The combination in a telephone system menace ling the selective' operatlon of said switch,

means for associating said registers with said line, a group of relays, means for successively associating said registers with said group of relays, means for sending impulses over said line, means responsive to such impulses for energizing a variable number of said relays, and means controlled by said group of relays for setting said registers.

9. The combination in a tele hone system of selective switches for extending telephone connections, a plurality of registers for controlling the I selective movement of said switches, a series of relays, means for successively associating said registers with said series of relays, means for successively energizing the relays of said series, means for maintaining the energization of said relays, and means dependent upon the number of relays energized for setting said registers.

10. The combination in a telephone system of selective switches for extending telephone connections, a plurality of registers or controlling the selective operation of said switches, a plurality of groups of electro-mec'hanisms, ineans for sucwsfsively operating the electro-mechanisms of each group, and means dependent on the number of electro-mechanisms 0 erated in said groups for variably positloning said regis- 11. The combination in a tale hone system of selective switches for extending telephone connections, a plurality of registers for controlling the selective operation of said switches, a plurality of groups of relays, means for sending series of impulses, means responsive to such impulses for successively energizing the relays of each of said groups, and means dependent on the number of relays operated in each of said groups for variably setting said registers.

12. The combination in a telephone system of subscribers lines, a selective switch for interconnecting said lines, means for extending a calling line to said switch, registers for controlling the selective movement of said switch, a plurality of groups of relays, means for sen ing impulses over said line, means responsive to such impulses for successively energizing a variable number of the relays of said groups, and means dependent on the number of relays of said groups that are energized for setting said registers;

1 13. The combination in a telephone system of selective switches for extending telephone connections, a plurality of registers for controlling the selective operation of said switches, a plurality, of groups of relays, means for successively associating said registers with each of said groups, and means controlled by said groups of relays for variably positioning said registers.

14. The combination in a telephone system of selective switches for extending telephone connections, a plurality of registers for controlling the selective operation of said switch, a plurality of groups of relays, a

circuit controlling switch for successively associating said registers with each of said groups, and means controlled by said oups of relays for variably positioning said registers.

15. The combination in a telephone system of selective switches for extendmg telephone connections, a series of registers for controlling the selective operation of said switches, a pluralit of groups of relays, means for successive y associating each of said grou of relays with alternate registers of said series of registers, and means controlled by said groups of relays for variably setting eacg register with which they are associate 16. The combination in a telephone system of selective switches for extending telephone connections, a series of registers for controlling the selective operation of said switches, a plurality of groups of relays, means for successively associating each of said grou of relays with alternate registers of said series of registers, means for ener 'zing a variable number of the relays in sai groups, and means dependent on the number of relays energized in each group for setting the registers with which such group is associated. v i

.17. The combination in. a telephone system of selective switches for extendlng telephone connections, a series of registers for controlling the selective operation of said switches, a plurality of groups of relays, an impulse circuit, means for successively associating each of said groups of relays both with said impulse circuit and with alternate registers of said series, means for sending impulses over said circuit, means res onsive to such impulses for energizing the re ays of said groups, and means controlled in accordance with the number of relays energized in each group for setting the registers with which such group is associated.

Inwitness whereof, I hereunto subscrlbe nay name this 1st day of December A. 1)., 1 19. a

FRANK N. REEVES. 

